Re: [022/119] highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE

Hugh Dickins
2009-12-07T01:11:59Z

On Sun, 6 Dec 2009, Greg KH wrote:

> 2.6.31-stable review patch. If anyone has any objections, please let us know.
>
> ------------------
> From: Soeren Sandmann <sandmann@daimi.au.dk>
>
> commit d4515646699b6ad7b1a98ceb871296b957f3ef47 upstream.
>
> Previously calling debug_kmap_atomic() with these types would
> cause spurious warnings.
>
> (triggered by SysProf using perf events)
>
> Signed-off-by: Soeren Sandmann Pedersen <sandmann@redhat.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: a.p.zijlstra@chello.nl
> LKML-Reference: <ye8vdhz8krw.fsf@camel23.daimi.au.dk>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

IIRC, this patch caused build failures in a number of architectures,
those which didn't already define KM_NMI, KM_NMI_PTE or KM_IRQ_PTE
e.g. compare the 2.6.32 arch/arm/include/asm/kmap_types.h against
its 2.6.31 version.

Should be fixable if you include the extras necessary, but I'm
ashamed to say I've left that as an exercise for the reader ;)

Hugh

>
> ---
> mm/highmem.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> --- a/mm/highmem.c
> +++ b/mm/highmem.c
> @@ -432,10 +432,15 @@ void debug_kmap_atomic(enum km_type type
> return;
>
> if (unlikely(in_interrupt())) {
> - if (in_irq()) {
> + if (in_nmi()) {
> + if (type != KM_NMI && type != KM_NMI_PTE) {
> + WARN_ON(1);
> + warn_count--;
> + }
> + } else if (in_irq()) {
> if (type != KM_IRQ0 && type != KM_IRQ1 &&
> type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ &&
> - type != KM_BOUNCE_READ) {
> + type != KM_BOUNCE_READ && type != KM_IRQ_PTE) {
> WARN_ON(1);
> warn_count--;
> }
> @@ -452,7 +457,9 @@ void debug_kmap_atomic(enum km_type type
> }
>
> if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ ||
> - type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ) {
> + type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ ||
> + type == KM_IRQ_PTE || type == KM_NMI ||
> + type == KM_NMI_PTE ) {
> if (!irqs_disabled()) {
> WARN_ON(1);
> warn_count--;
>
>
> --